Only the most dedicated mages will achieve master level skill in Restoration. Healthpotions in Skyrim are readily available and instantaneous in their effect. Pure casters probably won't have enough health to need spells beyond Close Wounds. Other than healing, Restoration spells are situational, useful against casters or undead. The Ward line tops out at the Adept level with Greater Ward, whose 80 point damage reduction is powerful midgame but is shattered almost instantly by high level casters or Elder and Ancient Dragons.

In short, Restoration arguably reaches its peak at Adept level and seems to increase extremely slowly relative to other skills. The high level anti-undead spells are quite powerful, but it is questionable whether they are worth the cost.

Find a forge and stand in the center of it. Now jump 5 or more times, then heal yourself. This is a safe and easy way to do this because the forge only hurts you when you first touch it. So if you walk up and stand on it, it will hit you once only. By jumping you get hit once for every time you land.

Find an area where you can sustain fall damage without completely killing your character. Fall, take damage, heal yourself, repeat.